Acuticosta Simpson, 1900 (original description)
Arcidens Simpson, 1900 (original description)
Arcidopsis Simpson, 1900 (original description)
Aurora Simpson, 1900 accepted as Diaurora Cockerell, 1903 (original description)
Bineurus Simpson, 1900 (original description)
Bullella Simpson, 1900 accepted as Alasmidonta Say, 1818 (original description)
Bulloideus Simpson, 1900 (original description)
Cafferia Simpson, 1900 (original description)
Callonaia Simpson, 1900 (original description)
Castaliella Simpson, 1900 (original description)
Caudiculatus Simpson, 1900 (original description)
Chamberlainia Simpson, 1900 (original description)
Chelidoneura Simpson, 1900 (original description)
Crassitesta Simpson, 1900 (original description)
Ctenodesma Simpson, 1900 (original description)
Cuneopsis Simpson, 1900 (original description)
Cyclomya Simpson, 1900 (original description)
Cylindrica Simpson, 1900 (original description)
Dalliella Simpson, 1900 (original description)
Discomya Simpson, 1900 (original description)
Dromus Simpson, 1900 (original description)
Epilobasma Simpson, 1900 accepted as Epioblasma Rafinesque, 1831 (original description)
Fusconaia Simpson, 1900 (original description)
Hyriana Simpson, 1900 (original description)
Laevirostris Simpson, 1900 (original description)
Lamprotula Simpson, 1900 (original description)
Lapidosus Simpson, 1900 accepted as Disconaias Crosse & Fischer, 1894 (original description)
Lens Simpson, 1900 (original description)
Micronaias Simpson, 1900 (original description)
Nasus Simpson, 1900 (original description)
Nepronaias Simpson, 1900 (original description)
Obovalis Simpson, 1900 (original description)
Pegias Simpson, 1900 (original description)
Physunio Simpson, 1900 (original description)
Pilea Simpson, 1900 accepted as Epioblasma Rafinesque, 1831 (original description)
Pilsbryoconcha Simpson, 1900 (original description)
Plethobasus Simpson, 1900 (original description)
Pletholophus Simpson, 1900 (original description)
Pressodonta Simpson, 1900 accepted as Alasmidonta Say, 1818 (original description)
Pseudavicula Simpson, 1900 (original description)
Pseudobaphia Simpson, 1900 (original description)
Pseudomutela Simpson, 1900 (original description)
Pseudoon Simpson, 1900 accepted as Obovaria Rafinesque, 1819 (original description)
Pseudoön Simpson, 1900 accepted as Pseudoon Simpson, 1900 accepted as Obovaria Rafinesque, 1819 (original description)
Pseudospatha Simpson, 1900 (original description)
Pterosygna Rafinesque, 1831 accepted as Pterosyna Rafinesque, 1831 accepted as Lasmigona Rafinesque, 1831 (original description)
Ptychoderma Simpson, 1900 (original description)
Ptychorhynchus Simpson, 1900 (original description)
Radiatula Simpson, 1900 (original description)
Rectidens Simpson, 1900 (original description)
Rugifera Simpson, 1900 accepted as Alasmidonta Say, 1818 (original description)
Schistodesma Simpson, 1900 (original description)
Spathopsis Simpson, 1900 accepted as Aspatharia Bourguignat, 1885 (original description)
Suborbiculus Simpson, 1900 (original description)
Trapezoideus Simpson, 1900 (original description)
Triquetrana Simpson, 1900 (original description)
Virgula Simpson, 1900 (original description)
Virgus Simpson, 1900 (original description)
Zaira Simpson, 1900 (original description)